Asteroids, sometimes called minor planets, are rocky remnants left over from the early formation of our solar system about 4.6 billion years ago. The current known asteroid count is: . Most of this ancient …

Asteroids and comets – and the meteors that sometimes come from them – are leftovers from the formation of our solar system 4.6 billion years ago.

Asteroids are leftover rocky parts of the solar system. collisions between asteroids – big and small. They tell Some have not changed very much in 4.5 billion years us about the formation and history of the …

Moons – also called natural satellites – come in many shapes, sizes and types. They are generally solid bodies, and few have atmospheres. Most planetary moons probably formed out the discs of gas and …

Apr 9, 2026 · NASA’s real-time science encyclopedia of deep space exploration. Our scientists and far-ranging robots explore the wild frontiers of our solar system.

Researchers have found that some near-Earth asteroids are actually burned-out comets, and most of them would have started out in the Kuiper Belt. Many comets crash into the Sun or the planets. …

The planetary system we call home is located in an outer spiral arm of the Milky Way galaxy. Our solar system consists of our star, the Sun, and everything bound to it by gravity – the planets Mercury, …

Discovery The first known interstellar object to visit our solar system, 1I/2017 U1 ‘Oumuamua, was discovered Oct. 19, 2017 by the University of Hawaii’s Pan-STARRS1 telescope, funded by NASA’s …

The brightest and largest object in our night sky, the Moon makes Earth a more livable planet by moderating our home planet's wobble on its axis, leading to a relatively stable climate. It also causes …

The surface is about 4 billion years old and it’s been pummeled, likely by comets and asteroids. Because the impact craters are still visible, scientists think the moon has little geologic activity—there …